1: <?php
  2: /**
  3:  * SimplePie
  4:  *
  5:  * A PHP-Based RSS and Atom Feed Framework.
  6:  * Takes the hard work out of managing a complete RSS/Atom solution.
  7:  *
  8:  * Copyright (c) 2004-2012, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors
  9:  * All rights reserved.
 10:  *
 11:  * Redistribution and use in source and binary forms, with or without modification, are
 12:  * permitted provided that the following conditions are met:
 13:  *
 14:  *  * Redistributions of source code must retain the above copyright notice, this list of
 15:  *    conditions and the following disclaimer.
 16:  *
 17:  *  * Redistributions in binary form must reproduce the above copyright notice, this list
 18:  *    of conditions and the following disclaimer in the documentation and/or other materials
 19:  *    provided with the distribution.
 20:  *
 21:  *  * Neither the name of the SimplePie Team nor the names of its contributors may be used
 22:  *    to endorse or promote products derived from this software without specific prior
 23:  *    written permission.
 24:  *
 25:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 26:  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 27:  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
 28:  * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 29:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 30:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 31:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 32:  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 33:  * POSSIBILITY OF SUCH DAMAGE.
 34:  *
 35:  * @package SimplePie
 36:  * @version 1.3
 37:  * @copyright 2004-2012 Ryan Parman, Geoffrey Sneddon, Ryan McCue
 38:  * @author Ryan Parman
 39:  * @author Geoffrey Sneddon
 40:  * @author Ryan McCue
 41:  * @link http://simplepie.org/ SimplePie
 42:  * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 43:  */
 44: 
 45: /**
 46:  * Used for data cleanup and post-processing
 47:  *
 48:  *
 49:  * This class can be overloaded with {@see SimplePie::set_sanitize_class()}
 50:  *
 51:  * @package SimplePie
 52:  * @todo Move to using an actual HTML parser (this will allow tags to be properly stripped, and to switch between HTML and XHTML), this will also make it easier to shorten a string while preserving HTML tags
 53:  */
 54: class SimplePie_Sanitize
 55: {
 56:     // Private vars
 57:     var $base;
 58: 
 59:     // Options
 60:     var $remove_div = true;
 61:     var $image_handler = '';
 62:     var $strip_htmltags = array('base', 'blink', 'body', 'doctype', 'embed', 'font', 'form', 'frame', 'frameset', 'html', 'iframe', 'input', 'marquee', 'meta', 'noscript', 'object', 'param', 'script', 'style');
 63:     var $encode_instead_of_strip = false;
 64:     var $strip_attributes = array('bgsound', 'class', 'expr', 'id', 'style', 'onclick', 'onerror', 'onfinish', 'onmouseover', 'onmouseout', 'onfocus', 'onblur', 'lowsrc', 'dynsrc');
 65:     var $strip_comments = false;
 66:     var $output_encoding = 'UTF-8';
 67:     var $enable_cache = true;
 68:     var $cache_location = './cache';
 69:     var $cache_name_function = 'md5';
 70:     var $timeout = 10;
 71:     var $useragent = '';
 72:     var $force_fsockopen = false;
 73:     var $replace_url_attributes = null;
 74: 
 75:     public function __construct()
 76:     {
 77:         // Set defaults
 78:         $this->set_url_replacements(null);
 79:     }
 80: 
 81:     public function remove_div($enable = true)
 82:     {
 83:         $this->remove_div = (bool) $enable;
 84:     }
 85: 
 86:     public function set_image_handler($page = false)
 87:     {
 88:         if ($page)
 89:         {
 90:             $this->image_handler = (string) $page;
 91:         }
 92:         else
 93:         {
 94:             $this->image_handler = false;
 95:         }
 96:     }
 97: 
 98:     public function set_registry(SimplePie_Registry $registry)
 99:     {
100:         $this->registry = $registry;
101:     }
102: 
103:     public function pass_cache_data($enable_cache = true, $cache_location = './cache', $cache_name_function = 'md5', $cache_class = 'SimplePie_Cache')
104:     {
105:         if (isset($enable_cache))
106:         {
107:             $this->enable_cache = (bool) $enable_cache;
108:         }
109: 
110:         if ($cache_location)
111:         {
112:             $this->cache_location = (string) $cache_location;
113:         }
114: 
115:         if ($cache_name_function)
116:         {
117:             $this->cache_name_function = (string) $cache_name_function;
118:         }
119:     }
120: 
121:     public function pass_file_data($file_class = 'SimplePie_File', $timeout = 10, $useragent = '', $force_fsockopen = false)
122:     {
123:         if ($timeout)
124:         {
125:             $this->timeout = (string) $timeout;
126:         }
127: 
128:         if ($useragent)
129:         {
130:             $this->useragent = (string) $useragent;
131:         }
132: 
133:         if ($force_fsockopen)
134:         {
135:             $this->force_fsockopen = (string) $force_fsockopen;
136:         }
137:     }
138: 
139:     public function strip_htmltags($tags = array('base', 'blink', 'body', 'doctype', 'embed', 'font', 'form', 'frame', 'frameset', 'html', 'iframe', 'input', 'marquee', 'meta', 'noscript', 'object', 'param', 'script', 'style'))
140:     {
141:         if ($tags)
142:         {
143:             if (is_array($tags))
144:             {
145:                 $this->strip_htmltags = $tags;
146:             }
147:             else
148:             {
149:                 $this->strip_htmltags = explode(',', $tags);
150:             }
151:         }
152:         else
153:         {
154:             $this->strip_htmltags = false;
155:         }
156:     }
157: 
158:     public function encode_instead_of_strip($encode = false)
159:     {
160:         $this->encode_instead_of_strip = (bool) $encode;
161:     }
162: 
163:     public function strip_attributes($attribs = array('bgsound', 'class', 'expr', 'id', 'style', 'onclick', 'onerror', 'onfinish', 'onmouseover', 'onmouseout', 'onfocus', 'onblur', 'lowsrc', 'dynsrc'))
164:     {
165:         if ($attribs)
166:         {
167:             if (is_array($attribs))
168:             {
169:                 $this->strip_attributes = $attribs;
170:             }
171:             else
172:             {
173:                 $this->strip_attributes = explode(',', $attribs);
174:             }
175:         }
176:         else
177:         {
178:             $this->strip_attributes = false;
179:         }
180:     }
181: 
182:     public function strip_comments($strip = false)
183:     {
184:         $this->strip_comments = (bool) $strip;
185:     }
186: 
187:     public function set_output_encoding($encoding = 'UTF-8')
188:     {
189:         $this->output_encoding = (string) $encoding;
190:     }
191: 
192:     /**
193:      * Set element/attribute key/value pairs of HTML attributes
194:      * containing URLs that need to be resolved relative to the feed
195:      *
196:      * Defaults to |a|@href, |area|@href, |blockquote|@cite, |del|@cite,
197:      * |form|@action, |img|@longdesc, |img|@src, |input|@src, |ins|@cite,
198:      * |q|@cite
199:      *
200:      * @since 1.0
201:      * @param array|null $element_attribute Element/attribute key/value pairs, null for default
202:      */
203:     public function set_url_replacements($element_attribute = null)
204:     {
205:         if ($element_attribute === null)
206:         {
207:             $element_attribute = array(
208:                 'a' => 'href',
209:                 'area' => 'href',
210:                 'blockquote' => 'cite',
211:                 'del' => 'cite',
212:                 'form' => 'action',
213:                 'img' => array(
214:                     'longdesc',
215:                     'src'
216:                 ),
217:                 'input' => 'src',
218:                 'ins' => 'cite',
219:                 'q' => 'cite'
220:             );
221:         }
222:         $this->replace_url_attributes = (array) $element_attribute;
223:     }
224: 
225:     public function sanitize($data, $type, $base = '')
226:     {
227:         $data = trim($data);
228:         if ($data !== '' || $type & SIMPLEPIE_CONSTRUCT_IRI)
229:         {
230:             if ($type & SIMPLEPIE_CONSTRUCT_MAYBE_HTML)
231:             {
232:                 if (preg_match('/(&(#(x[0-9a-fA-F]+|[0-9]+)|[a-zA-Z0-9]+)|<\/[A-Za-z][^\x09\x0A\x0B\x0C\x0D\x20\x2F\x3E]*' . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . '>)/', $data))
233:                 {
234:                     $type |= SIMPLEPIE_CONSTRUCT_HTML;
235:                 }
236:                 else
237:                 {
238:                     $type |= SIMPLEPIE_CONSTRUCT_TEXT;
239:                 }
240:             }
241: 
242:             if ($type & SIMPLEPIE_CONSTRUCT_BASE64)
243:             {
244:                 $data = base64_decode($data);
245:             }
246: 
247:             if ($type & (SIMPLEPIE_CONSTRUCT_HTML | SIMPLEPIE_CONSTRUCT_XHTML))
248:             {
249: 
250:                 $document = new DOMDocument();
251:                 $document->encoding = 'UTF-8';
252:                 $data = $this->preprocess($data, $type);
253: 
254:                 set_error_handler(array('SimplePie_Misc', 'silence_errors'));
255:                 $document->loadHTML($data);
256:                 restore_error_handler();
257: 
258:                 // Strip comments
259:                 if ($this->strip_comments)
260:                 {
261:                     $xpath = new DOMXPath($document);
262:                     $comments = $xpath->query('//comment()');
263: 
264:                     foreach ($comments as $comment)
265:                     {
266:                         $comment->parentNode->removeChild($comment);
267:                     }
268:                 }
269: 
270:                 // Strip out HTML tags and attributes that might cause various security problems.
271:                 // Based on recommendations by Mark Pilgrim at:
272:                 // http://diveintomark.org/archives/2003/06/12/how_to_consume_rss_safely
273:                 if ($this->strip_htmltags)
274:                 {
275:                     foreach ($this->strip_htmltags as $tag)
276:                     {
277:                         $this->strip_tag($tag, $document, $type);
278:                     }
279:                 }
280: 
281:                 if ($this->strip_attributes)
282:                 {
283:                     foreach ($this->strip_attributes as $attrib)
284:                     {
285:                         $this->strip_attr($attrib, $document);
286:                     }
287:                 }
288: 
289:                 // Replace relative URLs
290:                 $this->base = $base;
291:                 foreach ($this->replace_url_attributes as $element => $attributes)
292:                 {
293:                     $this->replace_urls($document, $element, $attributes);
294:                 }
295: 
296:                 // If image handling (caching, etc.) is enabled, cache and rewrite all the image tags.
297:                 if (isset($this->image_handler) && ((string) $this->image_handler) !== '' && $this->enable_cache)
298:                 {
299:                     $images = $document->getElementsByTagName('img');
300:                     foreach ($images as $img)
301:                     {
302:                         if ($img->hasAttribute('src'))
303:                         {
304:                             $image_url = call_user_func($this->cache_name_function, $img->getAttribute('src'));
305:                             $cache = $this->registry->call('Cache', 'create', array($this->cache_location, $image_url, 'spi'));
306: 
307:                             if ($cache->load())
308:                             {
309:                                 $img->setAttribute('src', $this->image_handler . $image_url);
310:                             }
311:                             else
312:                             {
313:                                 $file = $this->registry->create('File', array($img['attribs']['src']['data'], $this->timeout, 5, array('X-FORWARDED-FOR' => $_SERVER['REMOTE_ADDR']), $this->useragent, $this->force_fsockopen));
314:                                 $headers = $file->headers;
315: 
316:                                 if ($file->success && ($file->method & SIMPLEPIE_FILE_SOURCE_REMOTE === 0 || ($file->status_code === 200 || $file->status_code > 206 && $file->status_code < 300)))
317:                                 {
318:                                     if ($cache->save(array('headers' => $file->headers, 'body' => $file->body)))
319:                                     {
320:                                         $img->setAttribute('src', $this->image_handler . $image_url);
321:                                     }
322:                                     else
323:                                     {
324:                                         trigger_error("$this->cache_location is not writeable. Make sure you've set the correct relative or absolute path, and that the location is server-writable.", E_USER_WARNING);
325:                                     }
326:                                 }
327:                             }
328:                         }
329:                     }
330:                 }
331: 
332:                 // Remove the DOCTYPE
333:                 // Seems to cause segfaulting if we don't do this
334:                 if ($document->firstChild instanceof DOMDocumentType)
335:                 {
336:                     $document->removeChild($document->firstChild);
337:                 }
338: 
339:                 // Move everything from the body to the root
340:                 $real_body = $document->getElementsByTagName('body')->item(0)->childNodes->item(0);
341:                 $document->replaceChild($real_body, $document->firstChild);
342: 
343:                 // Finally, convert to a HTML string
344:                 $data = trim($document->saveHTML());
345: 
346:                 if ($this->remove_div)
347:                 {
348:                     $data = preg_replace('/^<div' . SIMPLEPIE_PCRE_XML_ATTRIBUTE . '>/', '', $data);
349:                     $data = preg_replace('/<\/div>$/', '', $data);
350:                 }
351:                 else
352:                 {
353:                     $data = preg_replace('/^<div' . SIMPLEPIE_PCRE_XML_ATTRIBUTE . '>/', '<div>', $data);
354:                 }
355:             }
356: 
357:             if ($type & SIMPLEPIE_CONSTRUCT_IRI)
358:             {
359:                 $data = $this->registry->call('Misc', 'absolutize_url', array($data, $base));
360:             }
361: 
362:             if ($type & (SIMPLEPIE_CONSTRUCT_TEXT | SIMPLEPIE_CONSTRUCT_IRI))
363:             {
364:                 $data = htmlspecialchars($data, ENT_COMPAT, 'UTF-8');
365:             }
366: 
367:             if ($this->output_encoding !== 'UTF-8')
368:             {
369:                 $data = $this->registry->call('Misc', 'change_encoding', array($data, 'UTF-8', $this->output_encoding));
370:             }
371:         }
372:         return $data;
373:     }
374: 
375:     protected function preprocess($html, $type)
376:     {
377:         $ret = '';
378:         if ($type & ~SIMPLEPIE_CONSTRUCT_XHTML)
379:         {
380:             // Atom XHTML constructs are wrapped with a div by default
381:             // Note: No protection if $html contains a stray </div>!
382:             $html = '<div>' . $html . '</div>';
383:             $ret .= '<!DOCTYPE html>';
384:             $content_type = 'text/html';
385:         }
386:         else
387:         {
388:             $ret .= '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">';
389:             $content_type = 'application/xhtml+xml';
390:         }
391: 
392:         $ret .= '<html><head>';
393:         $ret .= '<meta http-equiv="Content-Type" content="' . $content_type . '; charset=utf-8" />';
394:         $ret .= '</head><body>' . $html . '</body></html>';
395:         return $ret;
396:     }
397: 
398:     public function replace_urls($document, $tag, $attributes)
399:     {
400:         if (!is_array($attributes))
401:         {
402:             $attributes = array($attributes);
403:         }
404: 
405:         if (!is_array($this->strip_htmltags) || !in_array($tag, $this->strip_htmltags))
406:         {
407:             $elements = $document->getElementsByTagName($tag);
408:             foreach ($elements as $element)
409:             {
410:                 foreach ($attributes as $attribute)
411:                 {
412:                     if ($element->hasAttribute($attribute))
413:                     {
414:                         $value = $this->registry->call('Misc', 'absolutize_url', array($element->getAttribute($attribute), $this->base));
415:                         $element->setAttribute($attribute, $value);
416:                     }
417:                 }
418:             }
419:         }
420:     }
421: 
422:     public function do_strip_htmltags($match)
423:     {
424:         if ($this->encode_instead_of_strip)
425:         {
426:             if (isset($match[4]) && !in_array(strtolower($match[1]), array('script', 'style')))
427:             {
428:                 $match[1] = htmlspecialchars($match[1], ENT_COMPAT, 'UTF-8');
429:                 $match[2] = htmlspecialchars($match[2], ENT_COMPAT, 'UTF-8');
430:                 return "&lt;$match[1]$match[2]&gt;$match[3]&lt;/$match[1]&gt;";
431:             }
432:             else
433:             {
434:                 return htmlspecialchars($match[0], ENT_COMPAT, 'UTF-8');
435:             }
436:         }
437:         elseif (isset($match[4]) && !in_array(strtolower($match[1]), array('script', 'style')))
438:         {
439:             return $match[4];
440:         }
441:         else
442:         {
443:             return '';
444:         }
445:     }
446: 
447:     protected function strip_tag($tag, $document, $type)
448:     {
449:         $xpath = new DOMXPath($document);
450:         $elements = $xpath->query('body//' . $tag);
451:         if ($this->encode_instead_of_strip)
452:         {
453:             foreach ($elements as $element)
454:             {
455:                 $fragment = $document->createDocumentFragment();
456: 
457:                 // For elements which aren't script or style, include the tag itself
458:                 if (!in_array($tag, array('script', 'style')))
459:                 {
460:                     $text = '<' . $tag;
461:                     if ($element->hasAttributes())
462:                     {
463:                         $attrs = array();
464:                         foreach ($element->attributes as $name => $attr)
465:                         {
466:                             $value = $attr->value;
467: 
468:                             // In XHTML, empty values should never exist, so we repeat the value
469:                             if (empty($value) && ($type & SIMPLEPIE_CONSTRUCT_XHTML))
470:                             {
471:                                 $value = $name;
472:                             }
473:                             // For HTML, empty is fine
474:                             elseif (empty($value) && ($type & SIMPLEPIE_CONSTRUCT_HTML))
475:                             {
476:                                 $attrs[] = $name;
477:                                 continue;
478:                             }
479: 
480:                             // Standard attribute text
481:                             $attrs[] = $name . '="' . $attr->value . '"';
482:                         }
483:                         $text .= ' ' . implode(' ', $attrs);
484:                     }
485:                     $text .= '>';
486:                     $fragment->appendChild(new DOMText($text));
487:                 }
488: 
489:                 $number = $element->childNodes->length;
490:                 for ($i = $number; $i > 0; $i--)
491:                 {
492:                     $child = $element->childNodes->item(0);
493:                     $fragment->appendChild($child);
494:                 }
495: 
496:                 if (!in_array($tag, array('script', 'style')))
497:                 {
498:                     $fragment->appendChild(new DOMText('</' . $tag . '>'));
499:                 }
500: 
501:                 $element->parentNode->replaceChild($fragment, $element);
502:             }
503: 
504:             return;
505:         }
506:         elseif (in_array($tag, array('script', 'style')))
507:         {
508:             foreach ($elements as $element)
509:             {
510:                 $element->parentNode->removeChild($element);
511:             }
512: 
513:             return;
514:         }
515:         else
516:         {
517:             foreach ($elements as $element)
518:             {
519:                 $fragment = $document->createDocumentFragment();
520:                 $number = $element->childNodes->length;
521:                 for ($i = $number; $i > 0; $i--)
522:                 {
523:                     $child = $element->childNodes->item(0);
524:                     $fragment->appendChild($child);
525:                 }
526: 
527:                 $element->parentNode->replaceChild($fragment, $element);
528:             }
529:         }
530:     }
531: 
532:     protected function strip_attr($attrib, $document)
533:     {
534:         $xpath = new DOMXPath($document);
535:         $elements = $xpath->query('//*[@' . $attrib . ']');
536: 
537:         foreach ($elements as $element)
538:         {
539:             $element->removeAttribute($attrib);
540:         }
541:     }
542: }
543: